Manifold for downdraft carburetors



May 31, 1932. H. H. TIMIAN l I MANIFOLD FOR DQWNDRAFT CARBUBETORS 2 Sheets-Sheet l Filed Feb. 25. 1929 May 31, 1932. H. H. TIMIAN I MANIFOLD FOR DOWNDRAFT CARBURETQRS Filed Feb. 23, 1929 2 Sheets-Sheet 2 7x/E27 Ur SIB Patented May 3l, 1.932

man srATEs PATENT oFFlv-CE Ln n. TIMIAN, or INDIANAPOLIS, INDIANA, ,AssIeNon "ro WHEELEBFSCHEBLEB. oAnBunEfron co., or 1Nn1ANAroLIs, INDIANA, A conronA'rroN or INDIANA MANIFOLD FOB. DOWNDRAFT CARBURETORS This invention relates to an intake manifold system for internal combustion engines and has particular referencev to manifolds adapted to cooperate with down draft or inverted carburetors. With such a carburetor arrangement any fuel drippage or condensation is carried into the manifold system and th1s invention will be apparent from the disr the excess liquid fuel eventually works its way past the pistons \to dilute the lubricant in the crankcase of the engine.

It is an object of this inventionto provide a manifold drain having an automatic seal i or check valve operable when the engine is ,j revent the suction then existing in f in use to p thevmani 01d from drawing in air through the drain Fopening. When the usual accelerating pumps are properly used the engine absorbs the-excess fuel produced thereby, but when such pumps are improperly used as by repeated opening of the throttle when the engine is not running, the pumps inject quantities of raw fuel 'into the manifolding sys-- tem, causing pools of liquid to collect at low points `in the system. Similarly, the improper use of the usual choke or primer will cause a similar collection ofliquid fuel in the manifold. The presence qf such pools of liqid fuel result in making starting very di cult. It isaccordingly an objectr of this invention to provide means for drainin such accumulations of fuel' without inter ering with the-normal loperation of the intake m'anifoldingsystem.

It is another object of this invention to provide an improved manifolding system for down draft carburetors incorporating means assuring a more e ual distribution of the heavier liquid particles under both,id1ing and high speed conditions by arranging lthe. branches in such a way that at each point of division thedemand on the branches is equal in amount and alternating in= phase. To accomplish this result, I provide individual branches for each intake port which unite in pairs and then the paired branches Figure 3 is an elevation thereof with unite 'at a common carburetor flange, the points of division having an exhaust jacket or'hot spot and the branches sloping downwardly to the ports adjacent which are provided automatic traps and drains for liquid fuel.

Other and further important-objects of closures in the'specifcation andthe accom- T panying drawings. v f

This invention (in a preferredform) is illustrated in the drawings and hereinafter more fullyl described.

On the drawingsan A 4Figure 1 is an elevation of a manifold .embodying the features of this invention.

Figure 2 is atop plan view thereof with the carburetor omitted.

patsbroken away to show the branches and ex` haust jacket. y

Eigure 4 is a section on the -line IV-IV of- Figure 2. l

Figure 5 is a section 'on the line V--V of Figure 2.

Figure 6 is 'a section corresponding to Figure 5, but showing a modified form of drain valve. i

YAs shown on the drawings:

In Figure 1 the outline of an engine cylinder block-is referred 4to generally bythe reference numeral 10. A carburetor 11, of

the down draft type,. is' providedy with a mounting flange- 12, -at its bott0m the usual throttle'- lever 13,v air horn 14 and gasoline inlet connection 15 being shown.

The manifold illustrating'one embodiment of this invention has a carburetor mounting flange 16 to which the flange 12 is" bolted. The mountingiiange 16 is equally divided into two branches by a partition 17, the branches forming relatively short aligned vertical passages 18 and 19, which gradually change vfrom a semi-circular section into aV circular section adjacent the points where each passage connects to two downwardly and oppositely extending individual passages, numbered for the branches from the passage 18 and 2 for those branching from the passage 19. ach of the individual passages 20 and 21 is of uniform slope and terminates in a bend 22 having a .connecting passage 23 leading to a monnting flange 24 for attachmentto the intake ports formed in the cylinder block. Because the outer passages 20 are longer than the inner ones, their point of juncture is higher than thatof the inner passages, as clearly shown in Fig. 4.

In order to drainv off accumulations of fuel trapped in the intake manifolding system by interior leakage in the barburetor, improper use of the choke or mixture enriching device,

' or the usual accunulations of fuel on the walls of the manifold due to a wet mixture; a wall vor pocket 25 is formed in the passage 23, and a threaded drain drain openings are thus closed by the engine suction during the running of engine, but are free to open immediately upon stoppage of the enginelto drain o accumulated fuel, the presence ,of which rwould make restarting diiicult.' i

A manifold form of drain valve is shown in Figure 6 wherein the drain outlet opening 26 isenlarged to lform a chamber 32 above a nipplel 33 connecting to the drain tube 28.

" The upper end of the nipple 33 carries a number of short pins 34 supporting a light disc valve 35 which 'is adapted to be lifted by engine suction to close the outlet 26.

In order to asslst 1n a proper division of liquid fuel and toA vaporiz'e a portion thereof,

the juncture ofthe passages 18 and 19 with their branches-21 and 22 is envelo ed by a jacket or casing 36 havin a flanged) opening 37 on the en 'ne ,side to Iie bolted to an exhaust manifo d.

In the operation of the manifold of this invention, the arrangement of individually supplied'ports grouped Vin pairs at each point of division in the manifold with the ports alternating in their charging periods, assures Aa full and even` distribution of the fuel land air mixture to each port regardless of variations in the velocity of flow due to varying throttle openings and engine speeds.

`The manifold drain arrangement disposes of accumulations of fuel inside the intake outlet opening 26is provided in the bottom thereof to receive a Ipassaged nipple 27 tothe bottom of which The member 27' is provided with A updraft type of carburetor wherein any such liquid fuel drains back into the carburetor when the engine ceases operation. The manifold drain is provided with a check valve in order to prevent inflow of air to the manifold when the engine is in operation, the drain being open only when the engine has been stopped. l l

I am aware that many changes may be made, and numerous details of construction may be Varied through a wide range without departing from the principles of this invention, and I therefore do not purpose limiting the patent granted hereon, otherwise than necessitated by the prior art.

I claim as my invention:

1. In an intake manifolding .system for internal combustion engines, liquid fuel traps positioned 'at the low points therein and having drain openings therefrom, collecting means connecting said drain openings and leading to a common point of disposal, and check valves in said drain openings adapted to prevent back flow of air into said manifolding system when the engine is in operation.

2. An intake manifold adapted for use 4with downdraft carburetors, comprising .a

top inlet connection from the carburetor, downwardly sloping manifold branches leading therefrom, liquid traps formed at the lowermost points in said branches, and drain valves for said traps adapted to close when subjected to suction in said manifold.

4. A manifold adapted to secure uniform; mixture distribution from a down draft carburetor, comprising a common inlet having twin branches, downwardly extending twin branches from each original branch, all of said branches having equal drainage angles, individual intake port flanges associated with each of` said latter branches, liquid traps at the lowest points in said branches, liquid outlets from said traps, and non-return valves positioned in said outlets.

5. A manifold adapted to secure uniform mixture distribution from a down draft carburetor, comprising a common inlet having twin branches, downwardly extending twin branches from each original branch, individua-l intake port anges associated with each of said latter branches, liquid tra'ps et the lowest points in said branches, drainage openings from said traps, and check valves in said drain openings adapted to prevent back flow of airl into said manifolding system when the engine is in operation.

In testimony whereof I have hereunto subscribed my name at Indianapolis, Marion County. Indiana.

HAROLD H. TIMIAN. 

